Global effects of BKV infection on gene expression in human primary kidney epithelial cells.

BK virus (BKV) is a ubiquitous human pathogen that establishes a lifelong persistent infection in kidney epithelial cells. BKV reactivation within these cells results in a lytic infection in immunocompromised patients. Little is known about the specific interactions of BKV and the host cell during persistence and reactivation. We performed global cellular gene expression analyses using microarrays to characterize the global effect of BKV on primary kidney epithelial cells during the viral life cycle. Our results demonstrate that BKV primarily activates genes involved in cell cycle regulation and apoptosis (58% and 44% of upregulated genes at 48 and 72 h post-infection, respectively). Surprisingly, we observed that only four genes were downregulated during infection and that only two genes directly involved in the inflammatory response were differentially expressed. These results provide information about how BKV interacts with a cell type in which it both establishes persistence and undergoes lytic reactivation.